Developed by CISA, the Federal Bureau of Investigation, and international partners, this guidance describes how organizations can plan and execute clear, timely, accurate, and audience-appropriate communications during IT and operational technology (OT) outages. Whether caused by cyber threat actors, human error, equipment failure, or natural hazards, service outages can create disruption and societal panic even without speculation from end users and the public as added factors. Outages at one organization may cascade across interconnected systems, increasing uncertainty and alarm. The guidance emphasizes clarity, accountability, and transparency as core principles and details key elements of effective crisis messaging to inform affected stakeholders and the public while aligning with legal requirements, operational security, law enforcement, and containment efforts. 

CISA’s CI Fortify initiative provides information and resources that help critical infrastructure organizations prepare to isolate and recover vital OT systems during a major cyber incident or crisis. Changes in service availability, whether from outages or isolation as a defensive strategy, require transparent and ongoing communication to help end users minimize operational impact, limit speculation, and preserve trust. For emergency planning purposes, critical infrastructure owners and operators should assume that telecommunications services may be disrupted or otherwise unreliable, making it crucial for organizations to have crisis communications plans in place that integrate backup communication methods and understand the type of communication they should expect from their service providers.

https://www.cisa.gov/resources-tools/resources/communicating-under-pressure-best-practices-service-providers